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Data Centers: Say Hello to White Box Switch

Today, nearly all mainstream organizations use traditional (integrated) switches from vendors like Cisco, HP, Arista and Juniper. However, hyperscale folks such as Google, Amazon and Facebook are taking the lead to use white box switch in the portion of their networks, operating the system in a different manner. So what is the magic behind that? Are these OTTs the only customers of white box switch? You may find some hints in this article.

White Box Switch

What Makes White Box Switch Special?
White box switches consists of generic and inexpensive hardware and a preload network operating system (NOS) that can be purchased and installed separately. Often the hardware and software come from different vendors. This is in contrast to a traditional switch that comes as one package including the hardware and the software. For example, when you buy a catalyst switch from Cisco, you are obliged to use Cisco IOS as its operating system. But with white box switch, you are allowed to buy hardware and software separately.

Except offering increased software flexibility/programmability and reduced vendor lock-in, white box switch enables users to have multiple choices on hardware, network operating system (NOS) and applications. The impact of which is profound when it comes to network orchestration, routing, automation, monitoring and network overlay.
White Box Switch NOS

What About the Target Market of White Box Switch?
White box switch is initially designed for data centers. Companies that operating mega data centers are especially prefer white box switch for at least two reasons: these companies generally demand for massive deployment of switches and the port density of each switch needs to be high. White boxes are cheaper while offering high-density ports, hence proven to be an optimal alternative. On the other hand, these large-scale companies also value the flexibility and openness of the switch platform, besides CAPEX savings. As an open platform to offer broader flexibility, white box switch free them from traditional L2/L3 protocols, enabling more possibilities to develop and support any SDN based networking.

So, are these large-scale OTTs the only target market for the white box switch? Definitely No!

Any small or medium-sized cloud based providers, or data center of service providers can consider deploy white box switches in data centers, concerning the cost savings and enhanced flexibilities compared with traditional switches. Also because of the familiar IT tools/ commands their technicians are used to. However, white box switches are not yet ready to offer all features and services that a service provider needs to offer, and not yet for deployment in non data center environments.

The Potential of White Box Switch
Based on an open platform, white box switch offers greater possibilities for innovation when compared with traditional networking gears. As the number of vendors that specialized in developing software began to soar, customers can choose from a range of software solutions with added functionality and reduced price.

White box switch becomes even popular in this age of SDN. In traditional switches, software and hardware are integrated into one package, which limits the network innovation greatly. SDN is here to decouple the software from hardware, helping speed shifts in networking. It resembles the standpoint of white box switching. Moreover, the advert of SDN also drives white box forward: when combined with SDN-centric designs, these deployments have resulted in dramatic improvements in automation, operational simplification, and faster innovation. These benefits are now being realized by enterprises of all sizes via commercially available SDN solutions.

Despite the fact that white box switches cannot be applied in non-data center environment for the time being, they are meeting their target market requirements successfully. The potential of white box switch cannot easily be underestimate, it is an ideal alternative that worth to be seriously considered at least for data center applications.

Dual-Fiber or Single-Fiber CWDM Mux Demux for Higher Capacity Need?

What would you do if your network capacity can not meet your requirement? Will you put more fibers or update your system? In fact, these two methods are not very recommendable. Why? As your fiber cabling infrastructure is limited for adding fibers and high cost is required for upgrading system, these two methods are unworkable or too expensive. Under this condition, using a pair of CWDM Mux Demux to build a CWDM system with higher capacity is highly recommended. The CWDM Mux Demux is regarded as a key component for a CWDM system, as shown below. It can be simply divided into two types, dual-fiber and single-fiber CWDM Mux Demux. To meet the higher capacity need of your system, this post will mainly introduce the basic knowledge of the dual-fiber and single-fiber CWDM Mux Demux and guide you find a suitable fiber optic Mux Demux for building your CWDM system.

CWDM system

Dual-Fiber CWDM Mux Demux

Dual-Fiber CWDM Mux Demux is a passive device multiplexing and demultiplexing the wavelengths for expanding network capacity, which must work in pairs for bidirectional transmission over dual fiber. It enables up to 18 channels for transmitting and receiving 18 kinds of signals, with the wavelengths from 1270 nm to 1610 nm. The CWDM transceiver inserted into the fiber optic Mux port should have the same wavelength as that of Mux port to finish the signal transmission. For instance, the two reliable 4 channel CWDM Mux Demux showed below use four wavelengths, 1510 nm, 1530 nm, 1550 nm and 1570 nm, their corresponding CWDM transceivers also features the same wavelengths.

Dual Fiber CWDM Mux Demux

When the connection above works, the left 4 channel dual-fiber CWDM Mux Demux uses 1510 nm, 1530 nm, 1550 nm and 1570 nm for transmitting 4 kinds of signals through the first fiber, while the right 4 channel dual-fiber CWDM Mux Demux features 1510 nm, 1530 nm, 1550 nm and 1570 nm for receiving the signals. On the other hand, the transmission from the right to left use the same wavelengths to carry another 4 signals through the second fiber, finally achieving the bidirectional signal transmission.

Single-Fiber CWDM Mux Demux

Single-fiber CWDM Mux Demux should be also used in pairs. One multiplexes the several signals, transmits them through a single fiber together, while another one at the opposite side of the fiber demultiplexes the integrated signals. Considering that the single-fiber CWDM Mux Demux transmitting and receiving the integrated signals through the same fiber, the wavelengths for RX and TX of the same port on the Single-fiber CWDM Mux Demux should be different. Hence, if the 4 channel single-fiber CWDM Mux Demux is used for CWDM system, 8 wavelengths are required, the twice time as that of the dual-fiber one.

Single Fiber CWDM Mux Demux

The working principle of single-fiber CWDM Mux Demux is more complicated, compared to the dual-fiber one. As shown in the figure above, the transmission from the left to right uses 1470 nm, 1510 nm, 1550 nm and 1590 nm to multiplex the signals, transmit them through the single fiber, and using the same four wavelengths to demultiplex the signals, while the opposite transmission carries signals with 1490 nm, 1530 nm, 1570 nm and 1610 nm over the same fiber. As for the wavelength of the transceiver, it should use the same wavelength as TX of the port on the CWDM Mux Demux. For example, when the port of a single-fiber CWDM Mux Demux has 1470 nm for TX and 1490 nm for RX, then a 1470nm CWDM transceiver should be inserted.

Dual-Fiber vs. Single-Fiber CWDM Mux Demux

We always consider whether an item is worth buying according to its performance and cost. In view of the performance, the single-fiber CWDM Mux Demux can carry signals through only one fiber supporting fast speed transmission and saving the fiber resource, while the dual-fiber one requires two fibers for transmission with a higher reliability. Besides, using single-fiber CWDM Mux Demux can be easier to install. In view of the cost, the single-fiber CWDM Mux Demux is much more expensive than the dual-fiber. And the simplex fiber cable also costs higher than duplex fiber cable. Thereby, the whole cost for building single-fiber CWDM system must be much more higher. Like the two sides of the same coin, both the dual-fiber and single-fiber CWDM Mux Demux have their own advantages and disadvantages. Which one you should choose just depends on your system needs and your budget for building the CWDM system.

Pre-terminated Copper Cables: Interconnect & Cross Connect Solution

Copper cables are regarded as the optimal solution for data center, which provides significant benefits in the respect of capital expenditures, operating expenditures, performance, and reliability. Pre-terminated copper cable assemblies, emerging as a new copper cabling option for network architectures such as MoR (Middle of Row) or EoR (End of Row), are recommended for interconnect and cross-connect applications in data center.

What Is Pre-terminated Copper Cable Assemblies ?

Pre-terminated copper cable assemblies consisting of pre-terminated copper trunks and copper patch cords (usually terminated with RJ45 connector), are ideal for data center applications which  require high-efficient deployment. Being factory pre-terminated and strictly tested, the pre-terminated copper cable assemblies simplify network installation and maintenance, saving users much time and energy. Moreover, they offer more flexibility to be disassembled and repurposed to accommodate MACs (moves, adds and changes), facilitating management when rapid network growth and migration required.


Commonly used in point-to-point connections in data centers, pre-terminated copper trunk cables enable reliable connectivity between server and switch cabinets. While copper patch cords are used to connect panels to switches and servers. Moreover, intelligent patch cords are available to monitor port status.

Tips: various termination types are available for the pre-terminated trunks, such as jack-to-jack, jack-to-plug, plug-to-plug, cassette-to-cassette, and so on. So, your choice should base on the layout of the data center or telecommunications room, and the design philosophy employed.

How to Use Pre-terminated Copper Cable Assemblies?

Pre-terminated copper cable assemblies can be used in data center for backbone or intra-rack cable connectivity. This section illustrates the interconnect and cross-connect connectivity using pre-terminated copper cables in universal data center cabling applications.


For general data center cabling, copper trunk cables are used to make a permanent link between patch panels on each ends—one end is in a switch/network cabinet, and the other end is in a server/storage cabinet. And patch cords are usually used to interconnect the active equipment such as switches, servers, etc.


Cross Connect

In cross-connect cabling configuration, an individual patching area (often including two or more adjacent patch panels) is usually added between the switch/network cabinet and server/storage cabinet. Thus, two copper trunk cables are used as two permanent links between them. One runs from the switch/network cabinet panel to cross-connect panel, and the other one runs from cross connect panel to the panel in the server/storage cabinet. Copper patch cords are used to interconnect the active equipment and patch panels at the switch/network cabinet, cross-connect cabinet, and server/storage cabinet.


FS.COM Pre-terminated Copper Cable Assemblies Solution

FS.COM offers a wide range of configurable pre-terminated copper cable assemblies and patch panels to meet the demand for faster deployment and guaranteed performance in data center copper cabling, help saving time and money.

Pre-terminated Copper Cable Assemblies Pre-terminated Copper Trunk Cable
Copper Patch Cords Cat5e Patch Cord
Cat6 Patch Cord
Ca6a Patch Cord
Cat7 Patch Cord
Modular Patch Panel Cat5e Patch Panels
Cat6 Patch Panels
Other Accessories Cat5e Connector/Plugs
Cat6 Connector/Plugs
Cat7 Keystone Jacks & Plugs

Pre-terminated copper cable assemblies offer an ideal solution for data center interconnection and cross connect applications. All the pre-terminated copper cables, patch panels and related accessories presented in the above chart are available in FS.COM. For more details, please visit for contact us directly via

Understanding Polarity in MPO System

MPO/MTP technology, which is of high density, flexibility and reliability with scalable, upgradeable properties, is one of the contributors that lead the migration to 40/100GbE. However, the network designers face another challenge which is how to assure the proper polarity of these array connections using multi-fiber MPO/MTP components from end-to-end. Maintain the correct polarity across a fiber network ensures that a transmit signal from any type of active equipment will be directed to receive port of a second piece of active equipment – and vice versa. To ensure the MPO/MTP systems work with correct polarity, the TIA 568 standard provided three methods, which will be introduced in this article.

MPO Connector

To understand the polarity in 40/100 GbE Transmission, the key of MPO technology—MPO connector should be first introduced. MPO connector usually has 12 fibers. 24 fibers, 36 fibers and 72 fibers are also available. Each MTP connector has a key on one of the flat side added by the body. When the key sits on the bottom, this is called key down. When the key sits on top, this is referred to as the key up position. In this orientation, each of the fiber holes in the connector is numbered in sequence from left to right and is referred as fiber position, or P1, P2, etc. A white dot is additionally marked on one side of the connector to denote where the position 1 is. (shown in the following picture) The orientation of this key also determines the MPO cable’s polarity.

MPO/MTP connector

Three Cables for Three Polarization Methods

The three methods for proper polarity defined by TIA 568 standard are named as Method A, Method B and Method C. To match these standards, three type of MPO truck cables with different structures named Type A, Type B and Type C are being used for the three different connectivity methods respectively. In this part, the three different cables will be introduced firstly and then the three connectivity methods.

MPO Trunk Cable Type A: Type A cable also known as straight cable, is a straight through cable with a key up MPO connector on one end and a key down MPO connector on the opposite end. This makes the fibers at each end of the cable have the same fiber position. For example, the fiber located at position 1 (P1) of the connector on one side will arrive at P1 at the other connector. The fiber sequence of a 12 fiber MPO Type A cable is showed as the following:

Type A MTP Cable

MPO Trunk Cable Type B: Type B cable (reversed cable) uses key up connector on both ends of the cable. This type of array mating results in an inversion, which means the fiber positions are reversed at each end. The fiber at P1 at one end is mated with fiber at P12 at the opposing end. The following picture shows the fiber sequences of a 12 fiber Type B cable.

Type B cable

MPO Trunk Cable Type C: Type C cable (pairs flipped cable) looks like Type A cable with one key up connector and one key down connector on each side. However, in Type C each adjacent pair of fibers at one end are flipped at the other end. For example, the fiber at position 1 on one end is shifted to position 2 at the other end of the cable. The fiber at position 2 at one end is shifted to position 1 at the opposite end etc. The fiber sequence of Type C cable is demonstrated in the following picture.

Type C Cable

Three Connectivity Methods

Different polarity methods use different types of MTP trunk cables. However, all the methods should use duplex patch cable to achieve the fiber circuit. The TIA standard also defines two types of duplex fiber patch cables terminated with LC or SC connectors to complete an end-to-end fiber duplex connection: A-to-A type patch cable—a cross version and A-to-B type patch cable—a straight-through version.

Duplex patch cable

The following part illustrates how the components in MPO system are used together to maintain the proper polarization connectivity, which are defined by TIA standards.

Method A: the connectivity Method A is shown in the following picture. A type-A trunk cable connects a MPO module on each side of the link. In Method A, two types of patch cords are used to correct the polarity. The patch cable on the left is standard duplex A-to-B type, while on the right a duplex A-to-A type patch cable is employed.

Method A

Method B: in Connectivity Method B, a Type B truck cable is used to connect the two modules on each side of the link. As mentioned, the fiber positions of Type B cable are reversed at each end. Therefore standard A-to-B type duplex patch cables are used on both sided.

Method B

Method C: the pair-reversed trunk cable is used in Method C connectivity to connect the MPO modules one each side of the link. Patch cords at both ends are the standard duplex A-to-B type.

Method C


Network designer using MPO/MTP components to satisfy the increasing requirement for higher transmission speed, during which one of the big problems—polarity, can be solved by selecting the right types of MPO cables, MPO connectors, MPO cassette and patch cables. The three different polarization methods can be applied according to the satisfy requirements in different situations. For more information about polarity in MPO systems and 40/100GbE transmission polarity solutions, please visit Fiberstore tutorial at “Polarity and MPO Technology in 40/100GbE Transmission“.


MPO/MTP Connector – Multi-fiber Connector for High Port Density

In today’s transmission networks, small and multi-fiber connectors are replacing larger, older styles connectors for space saving. For example, the SC connector is gradually being replaced by its small version LC connector which allows more fiber ports per unit of rack space. To save space, multi-fiber connector is also a good solution, like MTP/MPO connectors. MTP/MPO connector allows more fiber ports per unit of rack space and also satisfies parallel optical interconnections’ needs for multi-fiber connection. This article is to introduce MPO/MTP connectors in details.

MPO Connector & MTP Connector

MT ferrule

MPO is short for the industry acronym—”multi-fiber push on”. The MPO connector is a multi-fiber connector which is most commonly defined by two documents: IEC-61754-7 (the commonly sited standard for MPO connectors internationally) and EIA/TIA-604-5 (also known as FOCIS 5, is the most common standard sited for in the US). MPO connectors are based on MT ferrule (showed in the picture on the right) which can provide quick and reliable high performance interconnections up to 4, 12, 24 or more and are usually used with ribbon fiber cables. The following picture shows diagram of MPO connectors, 12-fold (left) and 24-fold (right). The fibers for sending and receiving are colorcoded, red and green, respectively.


MTP stands for “Multi-fiber Termination Push-on” connector and it is designed by USConec and built around the MT ferrule. MTP connector is a high performance MPO connector designated for better mechanical and optical performance and is in complete compliance with all MPO connector standards. Some main improvements of MTP connector are as following:

  • The MTP connector housing is removable;
  • The MTP connector offers ferrule float to improve mechanical performance;
  • The MTP connector uses tightly held tolerance stainless steel guide pin tips with an elliptical shape;
  • The MTP connector has a metal pin clamp with features for centering the push spring;
  • The MTP connector spring design maximizes ribbon clearance for twelve fiber and multifiber ribbon applications to prevent fiber damage;
  • The MTP connector is offered with four standard variations of strain relief boots to meet a wide array of applications.
Application of MPO/MTP Connector

As mentioned, MPO/MPT connectors are compatible ribbon fiber connectors. MPO/MTP connectors cannot be field terminated, thus MTP/MPO connector is usually assembled with fiber optic cable. MTP/MPO fiber optic cable is one of the most popular MTP/MPO fiber optic cable assemblies, which are now being widely used in data center to provide quick and reliable operation during signal transmission. MPO/MTP connectors can be found in the following applications:

  • Gigabit Ethernet
  • CATV and Multimedia
  • Active Device Interface
  • Premise installations
  • Optical Switch interframe connections
  • Interconnection for O/E modules
  • Telecommunication Networks
  • Industrial & Medical, etc.
MPO/MTP Connector Selection Guide

The structure of MPO/MTP connector is a little complicated. The picture below shows the components of a MPO connector.

MPO connector components

With the drive of market requests. Various types of MPO/MTP connectors are being provided. Some basic aspects should be considered during the selection of a MPO/MTP connector are as following:


First is pin option. MPO/MTP connectors have male and female design (as showed in the picture on the left). Male connectors have two guide pins and female connectors do not. Alignment between mating ferrules of MPO/MTP connectors is accomplished using two precision guide pins that are pre-installed into the designated male connector. Second is fiber count: MPO/MTP connector could provide 4, 6, 8, 12, 24, 36, 64 or more interconnections, among which 12 and 24 are the most popular MPO/MTP connectors. In addition, like other fiber optic connectors, the selection of a MPO/MTP connectors should also consider fiber type and simplex or duplex design.

MPO/MTP Connector is a popular multi-fiber connector for high port density. It can offer ideal solution to set up high-performance data networks with the advantages of time saving and cost saving. As an important technology during migration to 40/100 Gigabit Ethernet, MTP/MPO connector is now being adopted by more and more data centers.